The meaning and calculation method of DVS for the sulfuric-nitric acid mixture used in nitration
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1. The meaning and calculation method of DVS for the sulfuric-nitric acid mixture used in nitration. 2. Are there any relevant parameters if sulfuric acid is replaced by phosphoric acid?
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The sulfuric acid dehydration value, abbreviated as “D.V.S” or “dehydration value”, refers to the calculated mass ratio of sulfuric acid to water in the waste acid at the end of the nitration process. D.V.S = mass of sulfuric acid in the waste acid / mass of water in the waste acid = mass of sulfuric acid in the mixed acid / (mass of water in the mixed acid + mass of water generated during nitration). The higher the dehydration value, the higher the sulfuric acid content or the lower the water content, and thus the greater the nitration capacity of the mixed acid.
DVS stands for dehydration value; it is a comprehensive indicator used to control the ratio of reactants and to assess the nitration capacity of a reaction. It plays a role in regulation during production, with values typically ranging between 2.1 and 2.3. For mixed acids: H2SO4; for waste acids: DVS = % sulfuric acid ÷ % water (all values are expressed as mass percentages). DVS = ─────────── H2O + HNO3 × 18/63. Here, sulfuric acid acts as a catalyst for the reaction; if phosphoric acid is used instead, I have not heard of such a scenario